Online dating services generally use textual search criteria to identify potential matches. Users of the dating services typically create a profile, including a textual description and one or more pictures of the user. Users can search for potential dates by searching the textual description portion of the other users' profiles. Text searching works well to search based on non-visual attributes (such as age, gender, ethnicity, and location of the user), but often falls short when searching based on physical appearance, including facial features. This is troublesome since physical appearance is generally considered one of the most important search criteria among users of online dating services. Text searching also suffers from the fact that users may misrepresent themselves in text, providing inaccurate descriptions of themselves. It is difficult to correct for these inaccuracies, since this behavior can vary across individuals, ages, and cultures.
Image-based searching has been used in other applications, such as facial-recognition, to ease the challenge of textually describing physical attributes. In such applications, images of faces are used as a query to search for other images of the same individual (i.e., the same person depicted in the image used as the query), but not other similar-looking individuals. Such applications typically do not allow users to search based on preferred facial features of the query image.